Fuel oil pump



July 9, 1940- A R. w. DoEG 2,207,002

FUEL OIL PUMP ATTORNEY.

R. W. DOEG FUEL OIL PUMP July 9, 1940.

2 Sheets-Shea?I 2 Filed June 20, 1938 W mqmmmml I .y nf@ n WIW/(2:1

. ATTORNEY.

Patented July 9, 1.940

' UNITED STATES PATENT OFFICE Kclvinator Corporation, Detrol poration of Maryland t, Mich., i corappummn :une zo. 193s, serial No. 214,835

Clam

The present invention pertains to oil burning apparatus, and. particularly, to new and improved means for controlling the flow and supply of oil.

One of the objects of the present invention is to provide motor-driven oil burning apparatus with an oil ow controlling means actuated by the rotor of the motor. v v

' Another object of my invention is to utilize, l in a motor-driven oil vburning apparatus, the

attraction effect upon the rotor of the magnetic field o f the stator for actuating an oil i'low control valve.

Another object is to provide a motor-driven oil burning apparatus with an oil ow control valve -means which is actuatedV to closed .position by axial movement of the motor rotor inone direction, upon deenerglzation of the motor stator, and which is allowed to actuate to open position, by axial movement inthe opposite direction of the rotor, upon energlzation of the stator due to the magnetic attraction of the stator eld upon the rotor.

Another object is to provide `an improved oil burning apparatus wherein oil-will flow at a constant ilxed pressure and volume.

Another object isto automatically supply the correct oil ratio by by-passing any excess oil to the suction side, of the supply pump.

Another object is the elimination of nozzle stoppage,`due to oil 'carbonization' during the shut-.down period, by draining the oil upon cessation of operation, to a. chamber removed from high temperatures.

Another object is to provide a structure where-V in all the parts arev combined into a compact4 -unitary structure, effecting a balanced and harmonious functioning of parts, while at the same time providing a unit that is easily and quickly adapted to various types of heating systems.

peculiarities of various types of heating systems.`

5 Another object is to provide an oil burning apparatus that is economical to manufacture, and

highly eiilcient/ in operation.

The invention itself, however, 'both as to its organization, and its method of operation together`with additional objects and advantages thereof, will best be underst from the following descriptionrof specizcv ents when read in conjunction with the accompanying drawings, in which: il Fis. 1 is a fragmentary cross sectional view of a heating system illustrating the present. invention applied thereto;

Fig. 2 is a vertical cross section of the oil burning apparatus shown in Fig. 1. y

Flg.3 is a fragmentary cross sectionalview 5 simili;i ar to Fig. 2 illustrating one phase of opera on;

Fig. 4 is a cross sectional view taken substantially on lines 0 4 of Fig. 2;

Fig. 5 is a. cross sectional view taken substanl0 tially on line 5-5 ofFlg. l;

Fig. 6 is a fragmentary cross sectional View taken substantially on line 6-6 of Fig. 4; and

Fig. 7 is a cross sectional view taken substantially on line 1 1 of Fig. 2.

Referring to the accompanying drawings in which like numerals refer to like parts throughout the several views, I have shown the invention adapted to an oil burning apparatus of the wall ame type wherein oil is discharged from 20 a rotating head across the combustion chamber for combustion at a peripheral region adjacent the combustion chamber wall. It is to be understood, however, that the invention is equally as adaptable to other types of motor-driven burn- 25 ers, such as for example, rotary burners of the suspension flame type, and to pressure atomization burners.

Referring to Fig. 2, an annular casing I0 having a closed end II and an open end is provided 30 to house the motor stator I2. The closed end II is formed with an axial portion I3 extending into the casing I0 and an axial stub I4 extending in Y the opposite direction. Theportion I3 and stub I0 are formed with a continuousaxial bore I5 to provide a journal for the motor shaft I6, which has a longitudinal passageway I1 extending from end to end.

I'he shaft I6 is provided with a peripheral shoulder I8 intermediate its ends and a threaded portion I9 spaced vabove the shoulder IB, as viewed in Fig. 2. Seating on the shoulder I8 is an inverted cup shaped element 2li. f

. The motor rotor .2| is carried by the shaft I6 intermediateA the shoulderA I8 and the screw 'a threads I9, and is recessed at one end at 2Ia toA rotor 2 I.

The shaft I6 is journalled in the bore I5 for axial as well as rotational movement, the lower end of the shaft projecting below the end face 24 of the stub I4, and the element 20 surrounding the axial journal element I3 in circumferentially spaced relation.

The open upper end of the casing I0 is closed by a dome-shaped cover 25 having an opening 26 therein through which the upper end of the shaft I'6 projects.

The shaft I6 is formed with a circumferential groove 21 having a passage 28 leading to the shaft passageway I1, and with a spiral groove 29, the upper termination of which communicates through passage 38 with the shaft passageway I1, the grooves 2l and 29 being within the bore I5.

A passageway 3| is providedthrough the axial portion I3 to place the bore I5 into communication with a chamber 32 provided within the casing I8 by an annular shell 33 secured to the closed end II by screws 34, the shell terminatinglin an inturned flange 35 somewhat above the flange 23 of the cup shaped element 20 in spaced relation.

The casing I0 is also provided with a drain passage 36 through its end wall II outside the stub I4.

Secured by means of screws 31 to the end face 24 of the stub I4, are, first an annular plate 38, second, a plate 39 having a -central aperture 48, and, last, a valve housing 4I, these parts having endwise engagement in the order named, as shown in Figure 2.

The valve housing 4I in the end which abuts the plate 33 is formed with a chamber 42 which is formed with a further chamber 43 of reduced diameter. Also, extending inwardly from one side of the member 4I is an oil inlet recess 44 extending across and intersecting the chamber 43 towhich an oil feed conduit 45 is connected by a nipple 46. The wall of the chamber 42 at its upper end is formed with diametrically opposite parallel grooves 41 for a purpose to be later described.

Arranged within the small diameter chamber 43 with a tight fit is a sleeve member 48 projecting upwardly into chamber 42 and having a bore 49 terminating in a valve port or restricted opening 59 at the bottom of the member 48, the member having an oil passage 5I communicating with the oil inlet recess 44 and opening int`o the bore 49. It is to be noted that the sleeve member 48 closes off the inlet recess or passage v44, and that one side of the member 48 is formed with a groove 52 registering with the inlet end of passage 44 to place this portion of the passage 44 into communication with the bottom 53 of the chamber 43 which lies below the end of the sleeve member 48.`

Arranged within the bore 49 of the sleeve member 48 is a slidable valve member 54 having a lower end of reduced diameter which terminates in a conical end 55 in axial alignment with the port 59 to close the same as shown in Figure 2.

The upper end of the valve member 54 projects above the sleeve member 48 and is formed with circumferential groove 456 of substantial width.

Arranged within the chamber 42 is a plate member 5.1 having an axial cylindrical portion 58 which terminates in a radial inwardly extending ange 59 extending into the circumferential groove 56. A stop 68 is provided across the top of the cylindrical portion and interposed between this stop and the bottom of aA recess 6I in the valve member 54 is a compression spring 62 which normally urges the plate member axially away from the valve member 54 into engagement with the upper side wall of the groove 56.

Also surrounding the sleeve member 48 and extending between the bottom of the chamber 42 and the plate member 51 is a compression spring 63, normally urging the plate member 51 upwardly whereby it holdsthe valve member 54 away from the port 58 in open valve position as shown in Figure 3, a snap ring 64 being provided to engage with the wall of the chamber 42 above the plate member 51 to serve as a stop for the plate member 51.

The wall of chamber 42 is provided with the previously described opposite parallel axial grooves 41 to loosely receive ears 66 formed on the plate member 51 which prevent rotation of the member 51.

'Ihe lower end of the shaft I6, as shown in Figures 2 and 3, projects through the annular member 38 and through member 39 into the chamber 42, it having bearing engagement with the `opening 40 in the member 39.

The lower end of the shat I6 is provided with a hardened end thrust member 61 threaded into the passage I1 and having bearing engagement with the plate member 51, as shown in Figures 2 and 3, the thrust member having a groove or slot 68 across its bearing face, and an axial passage 69 of small diameter opening into this slot and into the shaft passage I1, for a purpose to be later described.

The outlet side 10 of the inlet recess or passage 44 opens into an upwardly extending passage 1I terminating in an elongated suction port 12 in the upper face of the plate member 38, as shown in Figure 5, and in dotted outline in Figure 4.

Arranged within the bore 13 of the annular member 38 is a fuel pump which comprises an eccentric roller 14 provided with radial slots 15 within which suitable blades 16 are positioned to move radially outwardly by centrifugal force into engagement with the bore 13. The blades 16 are also assisted to engage the bore 13 by rings 11 which engage the rear of each blade 16 so that each blade, as it retracts into its slot 15 tends to cause the rings to assist the other blades to move radially outwardly.

The roller 14 surrounds the shaft I6 with sliding engagement and is provided with axial slots 18 into which the ends of a drive pin 19, extending through the shaft I6, project, whereby the shaft may move axially with respect to the roller 14 and yet drive the same.

The suction port 12 communicates, as shown in Figure 4, with the interior of the member 38. The oil isforced by the blades 14 through a discharge port 88 formed in the upper face of the annular plate 39, as shown in Figures 4 and 5, and through a passage 8I in the pump member 38 into a vertical passage 82 in thev stub which lcommunicates with a chamber 83 extending radially inwardly from one side of the stub I4. .The chambery 83 opens into the bore I5 through a port 84 of reduced diameter and has a ltering and metering device therein.

The ltering and metering device comprises a plug 85 adjustably threaded into the chamber 83 and supporting one end of a cylindrical screen 86. The opposite end of the screen has a tapered member 81 secured ythereto which is adapted to seat in and close the port 84. The tapered memaaoaooa 3 ber 81 is drilled to provide a metering passage cal adjusting screws |80 extending through the 88 opening from an enlarged bore 89 into the port nanges |28. 84. Also arranged within the enlarged bore 89 It will be noted that the shaft |6 extends upis a threaded plug 90 having a metering paswardly through the spool-like element |24 to a sage 9| therein. The chamber 88 is closed at point substantially above the top of the stack ||9 its outer end by a suitable closure plug 92 and is provided with a fuel and air distributing threaded therein. head |8I. n

In order to provide for a control of the output The fuel and air distributing head |3| comof the pump and to avoid fluctuation in oil prises a head portion |82 threaded to the upper pressure, I have provided a pressure relief mech- .anism, including a chamber 93 intersecting the passage 82 and communicating with a passageway 94 leading back to the suction inlet 12 through a passage 95 in the member 88. Ar-

end of the shaft I8 and having a central chamber |88 for receiving oil from the shaft passageway |1, from which chamber |33 a plurality of radially extending oil distributing tubes |34 project, as shown in Figures 1 and 2. Secured to the lranged in the chamber 93 between the passages top of the head portion |82 is a horizontal air 82 and-94 is a valve seat 96 having a port 91 defiecting plate |85 having fan blades |36'on its therethrough. under side arranged between the tubes |34.

.Threaded into the chamber 8841s a cup shaped The principle of operation of a wall flame type casing 98 having a passage 99 therethrough openoil burner is that the distributing head discharges, ing into an enlarged bore IUI of the casing, and within the combustion chamber andrawn in by slidablv' arranged 'within the passage I! is a neethefan blades and oil in a generally horizontal die valvearranged t Close 0r pen port 01- path to a zone of combustion near the combustion The outer end of the -valve stem lll projects chamber wall. To this end, I have provided the into the bore |88 of the casing 88 and carries a hearth plate ||1 with an inner annular flange |31 rigidly attached plate |02 to which one end 0f a and an outer annular flange |88, a metal band bellows |03 is secured in sealed engagement t0 |89 being telescoped with 'the flange or shoulder an annular plate |04. The plate lOl-has ttehed `|81 to extend to approximately they horizontal thereto an annular threaded member |88 and the plane of the top of the steek "9, plate |04 and member |85 are seated in a slightly by some suitable means such as soft solder |01, as band |39, the refraetery being a short distance shown in Figure 5. Threaded into the member below the upper edge of the band, as shown in is a threaded sleeve |08, which is locked Figure 1, Refraetery material |4| is also dieagainst movement by means 0f a 106k nut |03, posed between the band |39 and outer ange |88 and which has an Opening lll 0f reduced dill-lni below the upper edges thereof, and between the eter therethrough, whereby the interior of the ange |38 and boiler wan,

bellows |03 will be subjected to atmospheric pres- Telescope@ with the annular nange |33 and sure. resting upon the refractory body |4| is a second The bellows |03 with its plates|02and |04 forms annular band |42, preferably lof sheet metal, a chamber HI which is open to the atmosphere which extends upwardly into the path of the oil through the opening H0. A compression spring and air discharged from the distributing head H2 is disposed within thischamber between |3I. This band |42 serves as an ignition and the plates |02 and |04, and a second coil Spring vaporizing wall, which after the oil is ignited by H3 is arranged between the plate |82 and the` some such means as a gas pilot flame (not end 0f the Sleeve |09, the Pressure of which is shown), or a spark electrode |48, becomes heated adjustable by threading the sleeve |08 inwardly and vaporizes the intercepted oil. In order to A suitable body |40 of refractory is carried on enlarged portion |09 of the bore |88 and sealed the hearth plate n1 between the stack ||gl and or outwardly. n

AWhile the present invention is applicable to various types of oil burners such as the pressure atomization type and the suspension rotary type, I have shown the same, for the purpose of illustration, associated with an oil burner of the rotary wall llame type.

facilitate combustion, the band |42 supports suitable deflectors |44 in spaced relation, which serve to direct the vaporized mixture outwardly toward the boiler wall when combustion occurs in an annular ring of name, theband |39 serving to direct a portion of the air stream in an upward direction toward the vaporizing wall |42 for ad- To this end I have shown a boiler I4 mounted mixture with the vaporized oil. upon a suitable base IIS, having ahorizontal con- In the operation of the oil burner, particularly tinuous ange ||6 extending inwardly from the with respect to the present invention, the motor inner boiler Wall |50- Suitably Secured t0 this rotor 2|, when there is no demand for operation, ange ||6 is an annular hearth plate ||1 having that is, when the stator |2 is deenergized, has the a central opening ||8. A frusto-conical stack position shown in Figure 2, the weight of the ||9 is secured to the under side of the plate ||1', shaft I8 and rotor 2| being sunicient to overby screws |20, to extend through the opening ||8 into the combustion chamber formed by the inner boiler wall ||1.

Extending across thestack ||8 is an integral `web |2| having airflow apertures |22 therein,

come the resistance of the springs 62 and 63, with the result that the valve member 49 is forced to its lowermost position to close the oil port 50 and preclude the now of oil beyond the port 50. Also, in this position, oil flow is further 1prevented because the groove 21 and oil passageway 28 of the shaft |8 are not in registration with the passageway 84, but are closed by the bore I5, this insuring a double oil cut olf. When there is a demand for operation, the ro- Supported by the screws are a iairY of-de-f`tor" |2 is energized by well known controls (not pending brackets l 25 having horizontal flanges |26. The .motor casing |0 is provided with out'- wardly extending ear s`|21 having elongated openshown), and upon energization` a magnetic eld is created which, in addition to causing the rotor 2| to rotate, attracts the rotor and centralizes it ings |28 therein, the ears |21 seating upon vertiwith respect to the field, that is, the rotor, and15 shaft are raised, with the obvious result that the shaft passageway 28 is brought into registration with the passageway 86, and, that the spring 'I3 causes the valve member 49 to raise and open the port 5U. Consequently, rotation of the shaft I 6 causes the pump mechanism, previously described, to withdraw oil from the source of supply through inlet 44, port 50, passages 1l and 12, and discharge the same through outlet 80, passages 8| and 82, chamber 83, restricted passages 9| and 88 to the passageway 88 where it ows through shaft passage 28 to the passageway il and thence to the distributing tubes i343.

The relief valve mechanism, port 91 and valve stem IUI, as previously described, insures a constant oil pump output, that is, it insures that the oilzbeing supplied to the distributing tubes I3@ will fiow under a predetermined pressure without fluctuation, so that the proper relation between air and oil supply can be definitely controlled.

Lubrication of the rotor shaft I8 is effected throughthe spiral groove 29. Should, however, lubricant, that is, the fuel oil, flow above the journal I3, it will be directed by the sleeve 28 into the chamber 32 and thence through passage 3l for recirculation.

If, for any reason, oil should discharge into the casing Ill it will drain through the passage 35 in the casing ill.

Immediately upon deenergization of the stator l2, such as when the heat demand is satisfied, the rotor 2| and shaft i6 drop from the position shown in Figure 3 to the position shown in Figure 2 by reason of their combined weight, to interrupt the oil flow by closure of the port Sii and the groove 28. When this occurs, the oil in the shaft passage Il and tubes i3d will at once,

by reason of gravity, drain through passage 2@ and groove 29 into the chamber 32 and avoid any possibility of oil carbonization in the discharge tubes |34. Upon initiation of shaft operation, the spiral groove 29 pumps the drained oil baci: to the axial passage Il. During the operation of the burner, as the oil is drawn through the passage li past the unseated valve 55 it will have a tendency to create a partial vacuum in the chamber t2 that tends to eventually disrupt the flow of oil to the pump. The passage 69 and groove 68 permit communication between the shaft passage Il and chamber 42 whereby to allow oil to flow into the chamber 62 and seal the needle clearance in the sleeve 58 so that the pressure in the chamber 42 will never be less than atmospheric.

It is obvious from the foregoing that I have provided an oil burner mechanism that will insure a positive shut-'off of oil supply upon the demand for operation being satisfied; that'the ratio of oil and air supply can be positively controlled to insure the proper mixture; that a predetermined oil pressure can be maintained; that, during the shut down period, insurance is "had against carbonization, and that I have provided a compactness of parts which is conducive to economical an oil supply port opening into the bore thereof,

said shaft being axially movable within said bore, and an electric motor comprising a rotor xed to said shaft, and a stator, said rotor in the deenergized condition of said stator being axially offset with respect to said stator and said oil inlet passageway being closed by said bore, said rotor upon energization of said stator being movable .due to magnetic attraction into the magnetic eld of said stator whereby to axially move said shaft to bring said inlet passageway and oil port into oil flow registration.

2. In an oil burning apparatus, a shaft having an axial oil passage therein a circumferential oil inlet groove and a passageway opening into said passage and said groove, a journal for said shaft having its bore surrounding said groove and having an oil supply port opening into said bore, said shaft being axially movable within said bore, and an electric motor comprising a rotor fixed to said shaft and a stator said rotor normally being axially offset with respect to said stator and said groove normally being closed by said bore, said rotor being movable upon energization of said stator into the magnetic eld of said stator due to magnetic attraction whereby to axially move said shaft to bring said oil inlet groove into oil flow registration with said oil supply port.

3. In an oil burning apparatus, an electric motor having astator and a rotor axially movable upon energization of said stator into the.magnetic eld of said stator due to magnetic attraction and axially movable upon deenergization of said stator at least partially out of said field, an oil supinto the magnetic field of said stator due to magnetic attraction upon energization of said stator and axially movable at least partially out of said field upon deenergization of said stator, a shaft rigidly fixed to said rotor, a member having an oil supply passageway therein, and valve means associated with said passageway for opening and closing the same, said shaft being in engagement with said valve means for actuating the same upon axial movement of said rotor.

- 5. In an oil burning apparatus, an electric motor having a stator and a rotor axially movable into the magnetic field of said stator due to magnetic` attraction upon energization of said stator and axially movable at least partially out of said eld upon deenergization of said stator, a shaft rigidly xed to said rotor, said shaft having an axial oil passage therein, a member having an oil supply passageway, for supplying oil to said shaft passage, valve means associated with said supply passageway for opening and closing the same, said shaft being in engagement with said valve means for actuating the s ame upon axial movement of said rotor to open said supply passageway upon energization of said stator and'to close said supply passageway upon deenergization of said stator.

6. In anoil burning apparatus, an electric motor having 'a stator and a rotor axially movable into the magnetic field of said stator due tomagnetic attraction upon energization of said stator and axially movable at least partially out of said eld upon deenergization of said stator, a shaft rigidly fixed to said rotor, a casing member having an oil supply passageway therein, and valve means associated with said passageway for` opening and closing the same, said valve means includingspring means urging said valve means to open passageway position, said shaft cooperating with said valve means upon deenerglzation of said stator to move the same against the pressure of said spring to closed passageway position.

7. In an oil burning apparatus, an electric motor having a stator and a rotor axially movable upon energization of said stator in a vertical direction into the magnetic field of said stator due to magnetic attraction and axially m'ovable upon deenergization of said stator by gravity at sageway, said shaft projecting into said member and having end bearing engagement with said valve means whereby upon deenergization of said stator to move said valve means to closed passageway position, and upon energization of said stator to permit said valve means to move to open passageway position.

8. In an oil burning apparatus, an electric motor having a stator and a rotor axially movable upon energization of said stator in a vertical direction into. the magnetic eld of said stator due to magnetic attraction and axially movable upon deenergization of said stator by gravity at least partially out of said iield, a shaft securely fixed to said rotor and axially movable therewith, a valve casing member having an oil supply passageway therein, and valve means carried by said member for opening and closing said passageway, said 'shaft projecting into said member and having end bearing engagement with said valve means whereby upon deenergization of said stator to move said valve means to closed passageway position, said valve means including spring means to move said valve means to open passageway position upon vertical axialv movement ofsaid shaft and rotor due to the magnetic attraction of said rotor during energization of said stator.

9. In an oil burning apparatus a casing member having a vertical bore therein, a shaft journalled in said bore and having an oil delivery passage therein, asecond member having an oil supply passageway in communication with said delivery passage, valve means for opening and closing said passageway,` said shaft having its lower end in engagement with said valve means and being. axially movable from a predetermined upper position to a predetermined lower position and in its said lower position holding said valve means in closed passageway position, and an electric motor-comprising a motor securely xed to said shaft and a stator, said rotor in said lower position of said shaft being axially offset downwardly with respect to the magnetic field of said stator and being movable axially upwardly due to magnetic attraction upon energization of said stator whereby to raise said shaft and permit said valve means to move to open passageway position.

10. In an oil burning apparatus, an electric motor having a stator and a rotor axially movable into the magnetic eld of said stator due to magnetic attraction upon energization of -said statorand axially movable at least partially out of said field upon de energization of said stator, a shaft rigidly xed to said rotor, said shaft having an oil passageway therein provided with an inlet port in the periphery thereof, means forming 8L journal for said shaft and having anroil texable with said dischargepassage for controlling .mv

passage communicating with the bore thereof,

said bore enclosing said inlet port and said shaft v being axially movable inI said bore to position said port into and out of registration with said oil passage, casing means associated with said journal means and having an oil supply passageway communicating with said oil passage, and valve means in said casing means for opening and closing said last named oil supply passageway, .said shaft during the deenergized period of saidstator holding said valve meansin closed passageway position and in such position holding said oil passage out oi' registration with said port, said shaft being axially movablewith said rotor upon energization of said stator to register said oil passage with said port and to permit said valve means to open said oil supply passageway.

11. In an oil burning apparatus, pump means l i gized period holding said valve means in closed passage position and upon alignment with said stator due tolmagnetic attraction through energization of said stator opening said valve means to open passage position.

12. In an oil burning apparatus, pump' means `for delivering oil for combustion, means forming an oil passage in communication with said pump means, valve means f or opening and closing said passage, an electric motor having a stator and a rotor axially movable with respect to said stator into and at least partially out of the magnetic eld thereof upon energization Aand deenergization, respectively, thereof, said rotor having a connection for actuating said pump means and a. connection with said valve means forcausing opening of said passage upon energization of said stator and closing of said passage upon deenergization of said stator.

13. In an oil burning apparatus, an oil pump for delivering oil for combustion, an oil supply passageway connected to the inlet of said pump, an axially movable shaft for operating said pump, an electric motor having a rotor securely xed to said shaft and a stator, said rotor being normally axially oiset with respect to the magnetic field of said stator and being arranged upon energization of said stator to be drawn axially into said eld by the magnetic attraction thereof, and means, responsive to the axial movementof said shaft for controlling theiiow of oil through said oil passageway.

14. In an oil burning apparatus, an oil pump,

-a discharge passageway for said pump for supplying oil for combustion, a shaft for`operating said pump, and an electric motor having a fixed stator and a rotor, said rotor being xed to said shaft and being normally axially offset with respect to the magnetic field of said stator and being arranged upon energization of said stator to be drawn axially into said eld to axially move said shaft, said shaft having an oil passage registhe ow of oil from said passageway in response to axial movementl of said rotor and shaft.-

15. In an oil burning apparatus, a casing means having a pressure pump for withdrawing oil from a source of supply, a motor for operating said pump, an oil discharge passage in said casing means leading from the discharge side of said pump, an intake passage for said pump, a port between said intake and discharge passages, and` a pressure differential valve means associated with said port, said valve means being responsive to the pressure of oil in said discharge passage to by-pass oil Ato said intake passage upon rise in pressure above a predetermined value.

16. In an oil burning apparatus of the rotary type, casing means, a motor driven shaft journalled in said casing means, an oil distributing head secured to said shaft, a fuel pumpcperable by said shaft, an intake passage for said pump, a discharge passage means for said pump for feeding oil to said distributing head, and means for predetermining the pressure 0f the oil being fed to said head comprising a by-pass passage communicating with said intake passage and said discharge passage means and a differential pressure valve means responsive to the pressure of the oil in said discharge passage mean for by-passing oil to said intake passage when the pressure thereof exceeds a predetermined value whereby to maintain a supply of oil to said head under constant predetermined pressure.

17. In an oil burning apparatus, a journal member having a vertical bore therein, a motor-driven shaft journalled in said bore and extending above the same, said shaft having an axial oil supply passage therein, means for supplying oil to said axial passage, and means for draining oil from at least the upper portion of said axial pas sage upon cessation of operation of said shaft.

18. In an oil burning apparatus, a journal member having a vertical bore therein, a motor-driven shaft journalled in said bore and extending above the same, said shaft having an axial oil supply passage therein, means for supplying oil to said axial passage, and means for draining oil from at least the upper portion of said axial passage upon cessation of operation of said shaft and for returning the drained oil to said shaft upon initiation of operation of said shaft.

19. In an oil burning apparatus, a journal member having a vertical bore therein, a motor-driven shaft journalled in said bore and extending above the same, said shaft having an axial oil supply passage therein, means for supplying oil to said axial passage; and means for draining oil from at least the upper portion of said axial passage upon cessation of operation of said shaft, said last named means including an oil receiving reservoir communicating with said bore and a passage in said sh'aft communicating with said reservoir and with said axial passage at an elevation above said reservoir.

20. In an oil burning apparatus, a journal member having a vertical bore therein, a motor driven shaft journaled in said bore and extending above the same, said shaft having an axial oil supply passage therein, means for supplying oil to said axial passage, and means for draining oil from at least the' upper portion of said axial passage upon cessation of operation of said shaft `and for returning the drained oil to said shaft upon initiation of operation of said shaft.

RALPH W. DOEG. 

